Give the equation of each circle below in graphing form. .

1. A circle with center $(0,0)$ and radius $6$.

   Hint (a):

   Remember the general equation for a circle is $(x−h)^2+(y−k)^2=r^2$ where $(h,k)$ is the center.

2. A circle with center $(2,−3)$ and radius $6$.

   Hint (b):

   See part (a).

3. A circle with equation $x^2+y^2−8x+10y+5=0$.

   Hint (c):

   Complete the squares for $x$ and $y$.

   More Help (c):

   Rearrange the equation:
   $x^2−8x+$ _______ $+y^2+10y+$ _______ $=−5+$ _______ $+$ _______

   Answer (c):

   $(x−4)^2+(y+5)^2=36$